1. Field of the Invention
The present invention relates to bicycles and more particularly to a bicycle featured a detachable frame with improved characteristics.
2. Description of the Prior Art
Conventionally, bicycles can be classified as ones featured a fixed frame and ones featured a foldable frame (e.g., folding bicycles). For the former, head tube, fork, crossbar, down tube, seat tube, and seat stay thereof are welded together. Thus, they are superior in a strong structure and less restrictions imposed on designs. For example, bicycles featured a popular rhombic frame are made possible. But they are also inferior for occupying space in delivery and/or storage. This is particularly true for electric bicycles having longer length and being heavier. Nowadays, many cars have a rack for fastening a bicycle on the top or the rear of the car so that a driver can carry the bicycle while going for an outing. However, the fastening process is tedious. Further, it may adversely affect safety while driving.
For the latter (i.e., folding bicycles), a hinge mechanism is provided in an intermediate portion thereof so that a folding is made possible thereat. They are superior in saving space in delivery and/or storage. They are particularly suitable for being carried by cars for outings. But they are also inferior for being structurally weak because a potential break may occur at the folded portions of the bicycle. For overcoming such problem, reinforcement is added at the folded portions. Unfortunately, such reinforcement may detract the bicycle's appearance because many restrictions may be imposed on the design of bicycle due to the provision of the hinge mechanism. As a result, only a few types of folding bicycles are popular in the market. Further, some folding bicycles even have an increased width after folded. This can compromise the desired purpose of saving space in delivery and/or storage. Hence, a need for improvement exists.